Harry Potter and the Methods of Rationality

"I do hope," said Professor Quirrell, "that you prepared another wish, if I could not grant that one."

There was another pause.

Harry drew a deep breath. "I didn't," he said, "but I already thought of another one." Harry Potter turned to look out at the audience, and his voice firmed as he spoke. "People fear traitors because of the damage the traitor does directly, the soldiers they shoot or the secrets they tell. But that's only part of the danger. What people do because they're afraid of traitors also costs them. I used that strategy today against Sunshine and Dragon. I didn't tell my traitors to cause as much direct damage as possible. I told them to act in the way that would create the most distrust and confusion, and make the generals do the most costly things to try and stop them from doing it again. When there are just a few traitors and a whole country opposing them, it stands to reason that what a few traitors do might be less damaging than what a whole country does to stop them, that the cure might be worse than the disease -"

"Mr. Potter," said the Defense Professor, his voice suddenly cutting, "the lesson of history is that you are simply wrong. Your parents' generation did too little to unify themselves, not too much! This whole country almost fell, Mr. Potter, though you were not there to see it. I suggest that you ask your dorm-mates in Ravenclaw how many of them have lost family to the Dark Lord. Or if you are wiser, do not ask! Do you have a wish to make, Mr. Potter?"

"If you don't mind," said the mild voice of Albus Dumbledore, "I should like to hear what the Boy-Who-Lived has to say. He has more experience than either of us at stopping wars."

A few people laughed, but not many.

Harry Potter's gaze moved to Dumbledore, and he looked considering for a moment. "I'm not saying you're wrong, Professor Quirrell. In the last war, people didn't act together, and a whole country almost fell to a few dozen attackers, and yes, that was pathetic. And if we make the same mistake next time, yes, that'll be even more pathetic. But you never fight the same war twice. And the problem is, the enemy is also allowed to be smart. If you're divided you're vulnerable in one way; but when you try to unite, then you face other risks, and other costs, and the enemy will try to take advantage of those, too. You can't stop thinking at just one level of the game."

"Simplicity also has a great deal to commend it, Mr. Potter," said the dry voice of the Defense Professor. "I do hope that you have learned something this day about the dangers of strategies more complicated than uniting your people and attacking your enemy. And if all this does not tie into your wish somehow, I shall be quite annoyed."

"Yes," said Harry Potter, "it was pretty difficult coming up with a wish to symbolize the costs of unity. But the problem of acting together isn't just for wars, it's something we have to solve all our lives, every day. If everyone is coordinating using the same rules, and the rules are stupid, then if one person decides to do things differently, they're breaking the rules. But if everyone decides to do things differently, they can. It's exactly the same problem of everyone needing to act together. But for the first person who speaks out, it seems like they're going against the crowd. And if you thought that the only important thing was that people should always be unified, then you could never change the game, no matter how stupid the rules. So my own wish, to symbolize what happens when people unite in the wrong direction, is that in Hogwarts we should play Quidditch without the Snitch."

"WHAT?" screamed a hundred voices in the crowd, as Draco's jaw dropped.

"The Snitch ruins the whole game," said Harry Potter. "Everything the other players do ends up being irrelevant. It would make overwhelmingly more sense to just buy a clock. It's one of those incredibly stupid things you don't notice just because you grew up with it, that people only do because everyone else is doing it -"

But by that point Harry Potter's voice could no longer be heard, because the riot had started.

The riot ended around fifteen seconds later, after a gigantic spout of fire blasted out of the highest tower of Hogwarts to the sound of a hundred thunders. Draco hadn't known Dumbledore could do that.

The students sat down again very carefully and quietly.

Professor Quirrell was laughing, without pause. "So be it, Mr. Potter. Your will be done." The Defense Professor paused deliberately. "Of course, I only promised one cunning plot. And that is all that the three of you will get."

Draco had been half-expecting the words earlier, but now they still came as a shock; Draco exchanged rapid glances with Granger, they would have been the obvious allies but their wishes were directly opposed -

"You mean," said Harry, "we have to all agree on a wish?"

"Oh, that would be far too much to ask," said Professor Quirrell. "The three of you have no common enemy, do you?"

And for one brief moment, so fast that Draco thought he might have imagined it, the Defense Professor's eyes flicked in the direction of Dumbledore.

"No," said Professor Quirrell, "I mean that I shall grant three wishes using a single plot."

There was a confused silence.

"You can't do that," Harry said flatly from beside Draco. "Not even I can do that. Two of those wishes are mutually incompatible. It's logically impossible -" and then Harry cut himself off.

"You're a few years too young to tell me what I can't do, Mr. Potter," said Professor Quirrell, with a brief dry smile.

Then the Defense Professor turned back to the watching students. "Truthfully, I have no confidence in your ability to learn this day's lesson. Go home, and enjoy your time with your families, or what's left of them, while they still live. My own family is long since dead at the Dark Lord's hand. I shall see you all when classes resume."

In the speechless silence that resulted, Professor Quirrell already turning to walk off the stage, Draco heard the Defense Professor's voice say, quietly and no longer amplified, "But you, Mr. Potter, I would speak to now."

Chapter 35: Coordination Problems, Pt 3

They had gone to the Defense Professor's office, and Professor Quirrell had sealed the door before he leaned